I have often read that logical positivism holds only empirical data to be valid, yet as this view can't be empirical confirmed, it refutes itself. Is this true?

  • Perhaps "contradictory" is not the correct approach. See Logical Empiricism for discussion of Verificationism, and Anti-metaphysics with ref to A.J.Ayer's 1936 booklet: Language, Truth, and Logic and the discussion about "the persistent criticism that verificationism is self-undercutting" as well as Carnap's Principle of Tolerance. Feb 21, 2017 at 8:39
  • Can't be empirically confirmed? All our buildings and towers are built upon Newton's laws, the dangers of super-resistant bacteria are known after Darwin's laws, all plastics and new chemical materials are drawn from century-old chemistry. At the same time, two thousand years old religion keeps promising something they'll never give (salvation), because they can't. What is there yet to be confirmed?
    – Rodrigo
    Feb 21, 2017 at 14:54
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  • @Rodrigo How does any of that confirm logical positivism?
    – Conifold
    Feb 21, 2017 at 21:29
  • @Conifold I thought "logical positivism" was essentially the same "positivism".
    – Rodrigo
    Feb 21, 2017 at 22:54

3 Answers 3


No, not contradictory, but in the words of A.J. Ayer to Bryan Magee, "nearly all of it was false." (From the show "Men of Ideas, episode six: "Logical Positivism and its Legacy")

MAGEE: Now logical positivism must have had actually some real defects. What do you now in retrospect think the main shortcomings of the movement were.

AYER: I suppose the greatest defect...is that nearly all of it was false. (hearty laughter from the two of them)

MAGEE: I think you need to say a little more about that.

AYER: Perhaps that’s being too harsh on it. I still want to say that it was true in spirit in a way, that the attitude was right. But if one goes for the details, first of all the verification principle never got itself properly formulated. I tried several times and it always let in either too little or too much, and to this day it hasn’t received a properly logically precise formulation. Then, the reductionism just doesn’t work. You can’t reduce statements, even ordinary simple statements about cigarette cases and glasses and ashtrays, to statements about sense data, let alone more abstract statements of science...If you go in detail very, very little survives. What survives is the general rightness of the approach.

You might enjoy David Rynin's 1956 address to the American Philosophical Association, "Vindication of L*G*C*L P*S*T*V*SM":

I pointed out at the beginning that to vindicate a position is not the same as to show that it is perfect, and we see the kind of imperfection that remains. It strikes me as minute enough so that one can with some justification adopt the Verifiability principle with a minimum of sacrifice of sentences that might be thought to be cognitively meaningful. To weaken it so as to include the relevant cases of mixed quantification is to introduce an extremely unclear notion of confirmation, one that seems of little if any use in the pursuit of knowledge. But if one chooses to weaken it in the manner indicated we are still left with a conception in some sense resting on the notion of truth conditions or something very much like it; and I daresay that most of those who object to the stronger version of the principle would not be very much more content with the weaker. ...

It is worth pointing out that the only prominent thinker committed to the Verifiability principle who was interested enough in ethics to bother to write a book on the subject, Moritz Schlick, emphatically did not treat ethical statements as meaningless, and on the subject of metaphysics wrote the following: "If one wishes to characterize every view which denies the possibility of metaphysics as positivistic this is quite unobjectionable, as a mere definition; and I should in this sense call myself a strict positivist. But this holds, of course, only under the presupposition of a special definition of 'metaphysics.'" (And concerning that special definition, he wrote "...it hardly agrees with the formulations usual in philosophic literature...") It was in fact a definition according to which metaphysical statements attempt to express what is not, in his sense, expressible, i.e. content.

If to be a logical positivist is to be one who adopts the Verifiability principle for use in dealing with the problem of the meaning and meaningfulness of statements as they function within the context of cognition then I am prepared to call myself one; but if it be to be one characterized by the above mentioned bad logic and worse manners I wish not to be called one. ...

It is often thought that the Verifiability principle is somehow especially wedded to sense data, that according to it only statements verifiable and falsifiable, or perhaps confirmable, in terms of the data of one or more of the five senses are meaningful. But this is surely not essential. How many senses there are and what constitute the data of sense are themselves not very well formulated question, and it would be much more illuminating I believe to define "the given" in terms of "ascertainable truth conditions" than the latter in terms of the former. Truth is our goal. What difference does it make in what form or what materials ascertainment comes to us, so long as it comes? It is certainly in some sense correct that all ascertainment comes to us through the confrontation of data of some kind; but let not the paucity of language blind us to the fact that there is more under heaven than is dreamt of in our vocabularies.

It is a misrepresentation to characterize logical positivism as only holding "empirical data to be valid." Logical positivism just holds that philosophy should aspire to the same sort of rigor as science.

We are like sailors who on the open sea must reconstruct their ship but are never able to start afresh from the bottom. Where a beam is taken away a new one must at once be put there, and for this the rest of the ship is used as support. In this way, by using the old beams and driftwood the ship can be shaped entirely anew, but only by gradual reconstruction.
-Otto Neurath (1921)

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    I think Ayer was referring to Quine's dissolution of the Analytic/Synthetic distinction when he said "is that nearly all of it was false", not to the self-refuting nature of the verification principle. Feb 21, 2017 at 18:34
  • @AlexanderSKing Did you watch the interview? After discussing central doctrines, Ayer describes what led him to write Language, Truth and Logic prior to Magee's question about "the main shortcomings of the movement". He is neither commenting upon Quine nor positing or responding to a claim of a purported "self-refuting nature of the verification principle" so I am not sure how you infer the comment as a reference to Quine.
    – MmmHmm
    Feb 21, 2017 at 20:04
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    Yes I did watch the interview - more than once :-) - I've brought it up myself elsewhere in the Phil SE. I think he is referring to Quine because "Two Dogmas of Empiricism" was considered, according to lectures I've heard, the definitive refutation of L.P. Other problems didn't sink the program, but Quine's paper was the proverbial nail in the coffin. It helped that Quine was close to the Vienna circle. See for example M. Murphey "The Development of Quine's Philosophy": Quine has been called the man who destroyed Logical Positivism; he might better be called the last Logical Positivist. Feb 21, 2017 at 20:48
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    @AlexanderSKing Isn't Magee's show great?
    – MmmHmm
    Feb 21, 2017 at 21:31
  • @AlexanderSKing Certainly as much is accurate regarding Quine & the legacy of Two Dogmas of Empiricism but I still think your comment is incorrect & that you are reading a reference to Quine into a text where he is not even alluded to until much later and even then only in passing (35m27s). The same could be said of Austen's "Sense and Sensibilia" as sense-data is discussed but Ayer is responding to Magee's question about the main shortcomings of LP, not those as identified by WVO Q.
    – MmmHmm
    Feb 21, 2017 at 21:32

No, at least not in the way you present in the body of your question. It seems there you are referring to the verification principle. The verification principle can be a definition for “meaningful” and contain no contradiction. One such example would be

A statement which is not a truth of logic is meaningful if and only if it is empirically verifiable.

This is valid as a definition regardless how uncomfortable one finds it. This statement is not empirically verifiable, but no stipulated definition is. The statement asserts it, itself, is not meaningful as it is not empirically verifiable, but this does not entail a contradiction; a statement can be meaningless without being contradictory.

Incidentally, if we wish to modify this principle so that it does not entail its own lack of meaning, we can do so conservatively...

A statement which is not a truth of logic or a definition is meaningful if and only if it is empirically verifiable.

We can also stipulate definitions and truths of logic are analytic, giving another flavor…

A statement which is not analytic is meaningful if and only if it is empirically verifiable.

One may may claim this form is rendered void by Quine’s dissolution of the analytic/synthetic distinction, but there are three relevant considerations here.

First, one would have to agree that Quine was successful in actually dissolving the analytic/synthetic distinction. There is some controversy here. Secondly, Quine himself, in his later years, admitted his claimed dissolution did not cause as much damage as he originally thought and argued there are cases where the analytic/synthetic distinction is meaningful. Finally, even if we grant the complete dissolution of the analytic/synthetic distinction, this last form is still not a contradiction in of itself (it may contradict other principles of some varieties of logical positivism or be meaningless when combined with other principles, but it is not a contradiction as is).

There may be many problems with logical positivism, but the verification principle entailing a contradiction need not be one of them.


Logical positivism is sort of self contradictory in a different way. It rejects assumptions about the existence of an underlying (observer independent objective) reality, but uncritically accepts the existence of empirical data. But often empirical data can only be collected, if there is at least some theory of an underlying reality. It is a bit like saying "the statistics says ..." without realising how much what the statistics say is influenced by how you asked the questions and how you interpreted the answers.

Edit Maybe the downvote is justified. I now tried to track down references for the critique of logical positivism expressed above. So far, the best source seems to be the critique of Ernst Mach's idea that a physical theory should only contain quantities which can be observed. The problem here is that it is unclear to which extend logical positivism subscribes to Ernst Mach's idea. Werner Heisenberg was confronted with that critique in 1926 by Albert Einstein (see Werner Heisenberg "Der Teil und das Ganze" Kapitel 5), but that doesn't mean that Einstein is the original author of that critique. Interestingly enough though, that critique cannot be applied to the original Copenhagen interpretation of quantum mechanics, since it explicitly accepts and uses classical physics as the mean to describe observations, i.e. empirical data. (Not sure whether this means that the original Copenhagen interpretation is not positivistic.)

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    "It rejects assumptions about the existence of an underlying (observer independent objective) reality" It does not deny observer independent entities, please read Ayer's Language, Truth and Meaning. If anything, it is the positivism of Ernst Mach does this, or Humean strong verification criteria, but both are rejected already by Vienna Circle in their original form so that weak verification criterion is put forward. May 21, 2020 at 10:18
  • Much of science is only indirectly verified by observation. If empirical observations (say of multiple trails in particle detectors) entail some kind of underlying reality (say, of decaying Higgs bosons in the LHC), then logical positivism does accept that underlying reality as verifiable. Jul 28, 2021 at 10:24

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